Core enterprises have always been the backbone of the industry cluster development, and their status can provide timely information for the decision of construction machinery industry development in our country. With engineering machinery industrial cluster as an object, data of 8 core enterprises from 6 cities of Changsha, Xuzhou, Changzhou, Xiamen, Jinan and Liuzhou were selected for analysis from the respect of niche concept. An enterprise niche system composed of 10 dimensions and 23 elements was established by factor analysis. Then, the niche indexes for core enterprises were obtained with catastrophe progression method. Results show that among those 8 core enterprises, XCMG Group is the fastest-growing enterprise, followed by Zoomlion Company Ltd and Shantui Construction Machinery Co Ltd. Among all influencing factors, the factor of enterprise development ability can bring the greatest impact on the enterprise niche, while the factor of enterprise scale has little impact.